The Sets of Replacement O-Rings for the TFV12, TFV12 Prince, TFV8 Baby, TFV8 Big Baby, Vape Pen 22, TFV8 Baby V2. each set includes 3PCS O-Rings and 1PC seal gasket. You can use the sealing kit to replace the old silicone O-rings, after replacing them, most leaking issues will be fixed.